Surface plasmon resonance (SPR) is widely applied for bio/ chemical sensing. The main problem for all sensors is accuracy and sensitivity enhancement. For SPR sensors the accuracy depends on the characteristics of the plasmon resonance. In this work, we study SPR excitation assisted by liquid crystal layer. We consider Kretshmann configuration where a liquid crystal is sandwiched between a prism and glass plate, while the gold layer is evaporated over the glass plate. We show that the Bragg reflection of cholesteric liquid crystals modifies the plasmon resonance in a way increasing the accuracy of its location. Also, features of plasmon resonance excitation are studied for chiral liquid crystals.
Optical vortices have been applied for the purpose of polarimetry measurement. Vortex polarimetry combines the features of null polarimetry and imaging Fourier polarimetry providing one shot measurement. Different polarimeter systems and limiting accuracy factors are discussed.